Process of producing substantially pure magnesium



Nov. 26, 1935.

Fig.1 I

F. HANSGIRG PROCESS OF PRODUCING SUBSTANTIALLY PURE MAGNESIUM Filed Dec. 28, 1933 2 Sheets-Sheet l WQU yl' l l "INVENTQQ I Patented Nov. 26, 1935 UNITED STATES PROCESS OF PRODUCING SUBSTANTIALLY j PURE MAGNESIUM Fritz Hansg-irg, Radenthein, Austria, assignor to American Magnesium Metals Corporation, Pittsburgh, Pa., a corporation of Delaware Application December 28, 1933, Serial No. 704,298

In Austria January 17, 1933 This application is a continuation in partof nay application Ser. No. 655,067, filed February 3. 1 33. i

My invention relates to a process of and apparatus for producing substantially pure magnesium.

Y One object of the present invention is to separate substantially pure magnesium from nonvolatile concomitant substances.

Another object of my invention is to enable magnesium to be distilled so as to condense the distillate as a liquid deposit.-

A further object of the invention is to provide a process of and apparatus for the distillation of material containing. metallic magnesium which can be carried on continuously.

The process forming the subject matter of in application Ser.-No. 655,067 comprises passing crude metallic magnesium or magnesiferous material high in magnesium through a heated zone in which magnesium is vaporized under the prevailing pressure conditions, removing the resulting vapor by a non-oxidizing gas from the heated zone, separating out dusty impurities from said vapor, thereafter passing the vapor into a condensation zone, and cooling-it to the condensation point. The vapor is preferably prevented from cooling below the solidification point of themag-- nesium by being heated on its wayto the condensing zone, and is then suddenly cooled to condensation point. t

The process performed in this manner has special reference to the refining of magnesium by distillation in a continuous working operation, the metal being condensed as a liquid deposit of maximum purity. If desiredithis process may be performed at reduced pressure.

While various types of apparatus might be employed for carrying .out this, process, a typical apparatus according to the original invention consists substantially of an externally heated distillation still, which is provided with a conveyor and connected, by means of a heated pipe line, with a condenser from which the molten magnesium runs off into' a collector, for example, through a barometric discharge, a filter being interposed between the said distillation chamber and the said condenser. The still, pipe line, filter, condenser, discharge and receiver are preferably housed in a common heating chamber, such as an electric radiation furnace.

According to the present invention, the magnesium vapors issuing from the distillation chamher are freed from impurities present in the form of dust while passing to the condenser by using rise to any irregularities during the process. I

Moreover the thermal economy of the process is improved because preheating the fresh filtering l0 material required for replenishing consumed material when using granular filters, is dispensed with. 1

For carrying out the present process dust removing apparatus of known construction in which 5 the dust is precipitated by the principle of reversal of the direction of flow and/or of reducin the velocity of flow, for example dust precipitators with baille plates or centrifugal (cyclone) gas cleaners can be inserted between the distillation 20 chamber and the condenser; the dust removing chambers of this apparatus must, however, be, heated in order to prevent any condensation of the metal vapors in the dust precipitators.

In order to complete the operation of the re- 5 moval of dust two or more such apparatus of identical or different construction can be placed side by side or dust precipitating chambers can be arranged in series in the path of flow of the vapors.

In order more clearly to understand the nature of the invention, reference is made to the accompanying drawings, which illustrate diagrammatically and by way of example, an embodiment of apparatus suitable for carrying out the process 35 of the invention.

In said drawings Fig. 1 is a vertical section taken on line II of Fig. 3; Fig. 2 a horizontal section along the line IIlI of Fig. 1; Fig. 3 a longitudinal section showing means for feeding 40 the material continuously.

A pipe 2 leads from the'middle of the distillation chamber i, through which the material to be distilled is continuously fed, tangentially into a cylindrical dust precipitating chamber 3, which tapers conically=in a downward direction. The lower end of the chamber is connected with the dust collecting space 4. The vertical limb of a bent pipe 5 passes through the centre of the cover of the chamber 3 and constitutes the connection 50 between said chamber and the condenser. 6. The vapors bathe the jacket of the hollow vessel 1, whereon condensation proceeds, the liquid metal being collected in the receiver.

The dust contained in the vapors which enter 55 the dust-removing chamber 3 is precipitated chiefly on the cylindrical jacket of the chamber by the action of centrifugal force and falls into the collecting space 4, whilst purifled vapors pass on to the condenser via pipe I.

The distillation can be effected either with or without'the aid of reduced pressure.

Thedistillation chamber l, dust separator 3,

condenser 6, and the pipes connecting them are disposed within a heating furnace 3, as referred to hereinabove, for example of the electric radiat v Various means may be used for moving the material to be distilled continuously through the distillation chamber, that shown being one of the means disclosed in my aforesaid application Serial No. 655,067. Having reference to Fig. 3, dis-. tillation chamber i is in the form of an elongate tubein which there is mounted a screw conveyor 3 to' which the material to be distilled is fed from a charging hopper i3 supplied with material from a storage binll through a lock chamber l2 controlled by valves l3 and it, so that material may be charged into hopper ill from storage bin I i while. preventing entry of air into the distilia Conveyors 3 and it may be driven continuously by any suitable means, for example through pulle'ys l1 and I8.

Distillation chamber i extends entirely through 'Tfurnace 3 and the distillation residue is discharged into a pipe I! through which it passes into acollecting chamber II, from which it is discharged through a lock chamber 2| controlled by valve members 22 and 23.

Collecting chamber 2|, lock chambers l2 and ii, and charging hopper I! may be connected with a vacuum pump, not shown; through pipes 24, II, 23 and 31 provided with valves for apply-' ing the vacuum to these units according to need. A stream of gas which is inert to metallic magnesium, suitably hydrogen, may be introduced into the apparatus to provide a flow for directing the flow of the magnesium vapors through pipe 2, d ust removing element 3,and pipe I, into con- "denser I, and to conduct the operation in an inert atmosphere. In the'apparatus shown, the inert gasis introduced through pipes 23 and 30 1 into both ends of distillation chamber I As shown in Fig. 3, the inert gas may be introduced as need be into lock chambers I2 and ii.

Mounted in condenser is a cylindrical tube 32- the lower end of which is closed by a curved bottom, the condenser being disposed so that the incoming vapors bathe its bottom surface.

' Mounted coaxially within tube 32 is a tube 33 also closed at its lower end and coaxially surrounding a tube 34 which is open at its lower end. Cooling fluid is introduced into tube 33, and is withdrawn from tube 33 through an outlet. Tube 33 is mounted close to but out of contact with the wall of tube 32, so that in condensation of -the magnesium vapor on tube 32 the removal of heat by the cooling medium circulated through tubes 33 and 3| takes place principally :by radiation. Tubes 33 and 34 are vertically adjustable within? tube 32, as shown, so that the cooling action may be regulated according to need. The outlet 33 from the condenser dips into a receiver 31 mounted within furnace 8 and provided with a flowcontrolling valve a. By arranging the condenser at a level more than six meters above the outlet level, a suitable automatic barometric outlet device is obtained.

. According to the provisions of the patent statutes, I have explained the principle and construction of m'y invention, an d have; illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that. within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically illustratedand described.

No claim is made herein to the apparatus described hereinabove .and shown in the drawings, this subject matter having been transferred to a divisional application flied rial No. 757,783.

What I claim is:'-

\ 1. The process for producing substantially pure magnesium which comprises heating material containing metallic magnesium to liberate magnesium vapor therefrom, removing the resulting vapor by a non-oxidizing gas .from the heated zone, separating out dust from said vapor by provoking variations of the flow oi the vapor capable of promoting deposition of the suspended solids owing to their natural gravity, and thereafter passing the vapor together with the non-oxidizing gas into a condensation zone, and cooling it to condensation point.

2. The 'process'for producing substantially magnesium whichx comprises heating material containing metallic magnesium to liberate magnesium vapor therefrom, removing the resulting 'vapor by a non-oxidising gas from the heated zone, separating out'dust from said vapor by re- 35 versing its direction of flow, and thereafter passing the vapor together with the non-oxidizing gas into a con on zone, and cooling it to condensation point.

3. The process for producing substantially pure magnesium which. comprises heating material containing metallic magnesium to liberate mag-' nesium vapor therefrom, removing the resulting vapor by 'a non-oxidizing gas from the heated zone, separating out dust from said vapor by reducing its velocity of flow, and thereafter passing the vapor togetherwith the non-oxidizing gas into a condensation zone, and cooling it to condmsation point. I

4. The process for producing substantially pure magnesium which comprises heating material 1 oontainingmetallidmagnesium to liberate magnesium vapor therefrom, removing the resulting vapor by a non-oxidizing gas from the heated zone, separating out dust from said vapor by reversing its direction and reducing its velocity of flow, and thereafter passing the vapor together witli the non-oxidizing gas into a condensation zone, and cooling it to condensation point.

5. A process for separating magnesium from non-volatile concomitant substances which comprises passing material containing metallic magnesium continuously through a heated zone to liberate magnesium vapor therefrom, carrying away the disengaged vapor by a non-oxidizing December 17, 1934, Se- 15- pure 30 erate magnesium vapor therefrom, carrying away the disengaged vapor by a non-oxidizing gas from the heated zone, separating out dust from the flowing vapor by provoking variations of the flow of thevapor capable of promoting deposition of the suspended solids owing to their natural gravity, and thereafter cooling it to condensation point, premature condensation being prevented by keeping the vapor on its way between the distillation and condensation zone at a temperature above the solidification temperature of metallic magnesium.

FRITZ HANSGIRG. 

